I've been slowly (very slowly) setting up a small store at Resistor to carry electronics parts and prototyping tools, since there aren't any retail stores in town where you can pick up an Arduino RIGHT NOW. While ordering parts and figuring out where it will all go, I had a vision:
Vending machine full of components!
I've been surfing Craigslist and eBay, and while I'm not allowed to bring any new equipment into the space until we're all settled in post-move, it looks like a used vending machine can be found for $300 – $700 depending on what you're looking for.
One of the old school snack machines sounds just about perfect, but the one we found can only handle prices up to $3.95. Most vending machine hacks I was able to find were about getting free stuff out of them, not modding them to sell out of. Another fun hack which probably wouldn't be terribly difficult would be hooking it up to the net and letting people pay with PayPal or credit card.
I'll continue to hunt for the perfect machine, but in the mean time I'd love to hear about any vending machine hacks folks have seen or done. Because clearly what we need a robot who sells robot parts!